Sedatives hypotonics

1. SEDATIVE HYPNOTICS
Sedatives are the drugs that produces a calming or
quieting effect and reduces excitement. It may
cause drowsiness.
Hypnotic is a drug that induces sleep resembling
natural sleep.
Both sedation and hypnosis may be considered as
different grades of CNS depression.
Sleep can be classified into two types depending on
the physiological characteristics:
 NREM (non rapid eye movement) sleep
 REM (rapid eye movement) sleep

2. CLASSIFICATION:
1) Benzodiazepines:
 Long acting: Diazepam, chlordiazepoxide, flurazepam
 Short acting: temazepam, lorazepam, triazolam
2) Barbiturates:
 Phenobarbitone, mephobarbitone, secobarbitone,
pentobarbitone.
3) Newer agents:
 Zolpidem, zopiclone.
4) Miscellaneous:
 Paraldehyde, chloral hydrate, glutethimide.

3. BENZODIAZEPINES:
 Chlordiazepoxide was the first BZD to be introduced
into clinical medicine.
 BZD’s are useful:
 Sedation and hypnotics
 Reduces anxiety
 Causes muscle relaxation
 Anticonvulsant effects
 Causes quick onset of sleep and increases the
duration of sleep.
 Quality of sleep resembles to natural sleep more
closely when compared to other hypnotics.

4. It also reduces anxiety and aggression and thus
produces a calming effect.
MOA: these drugs bind to BZD receptors and enhance
the effect of GABA-the inhibitory neurotransmitter.
Adverse effects: drowsiness, confusion, amnesia,
lethargy, impaired motor coordination such as driving
skills.
When compared to barbiturates, tolerance and
dependance of BZD’s are less, these are safer, donot
effect the respiratory and CV functions.

5. BARBITURATES:
These are the derivatives of Barbituritic acid.
Classified as:
 Long acting: phenobarbitone
 Short acting: pentobarbitone
 Ultra short acting: thiopentone
 MAO: these drugs bind to GABA receptors and
enhance the effect of GABA-the inhibitory
neurotransmitter.
 Causes sedation and induces sleep.
 Also reduces anxiety and impairs memory.

6. Adverse reactions: hangover may be accompanied by
nausea, vomiting, vertigo and diarrhoea. Hypotension,
depression of respiration, decreased excitability of
neuromuscular junction are also seen.
Tolerance is developed in patients with repeated
intake of barbiturates.
These drugs are used in sedation, hypnotics,
anaesthesia, pre anesthetic medication, as an anti-
epileptic, and in neonatal jaundice.

7. NEWER AGENTS:
Zolpidem is a hypnotic.
It is a non BZD drug.
Claimed to be a better hypnotic than other classes.
Adverse effects: drowsiness, confusion, amnesia,
lethargy, impaired motor coordination such as driving
skills.
Zopiclone is another hypnotic used
Actions resemble to BZD’s

8. MISCELLANEOUS:
Chloral hydrate is used as an alternative to BZD.
Has a bad taste and is an irritant.
Causes nausea, vomiting.
Produces hypnosis without affecting respiratory and
CV functions.
Paraldehyde is irritant and can dissolve plastic hence
cannot be given by plastic syringe.
It is a good hypnotic causing little hangover.
It can be given rectally, intramuscularly or orally.
Also has anticonvulsant properties.